Originally Posted by
maddog34
Ok.. but your 7 speed rear Wheel Hub won't accept a 9 speed Cassette....you will need a 8-9-10 sp. Freehub type rear wheel/hub... .And you'll need to measure the frame to see if it is a 130mm or 135 mm distance between the rear axle dropouts. Measure from inside face to inside face where the Rear Axle mounts to the bike frame... 135mm is good, 130mm makes things a bit tougher to upgrade to 9 speed.. what is your Wheel size again? 26" tire or 29"/700c?. And this is a good time to learn about the HUB types too... here's an article on how to tell the difference between freewheel and freehub setups...freewheels use a Threaded hub mount.. Freehubs use a lockring and splines, and the ratchet mechanism is part of the hub.
After reading this and looking at that article mine looks odd. With the wheel off there is a lock ring that has to be removed to remove the sprockets. There are individual sprockets that have spacers between them and they slide onto a two-stepped splined hub. The article says that freewheel sprockets are bolted together. Mine are not.